Normal range of maximum mouth opening in pakistani population: A cross-sectional study

Abstract

Aims and Objectives: Maximum mouth opening (MMO) is an important diagnostic reference for dental clinicians as a preliminary evaluation and an indicator of function of masticatory system and temporomandibular joints. This aim of this study was to describe the normal mouth opening of Pakistani population and its possible correlation with sex and age. Materials and Methods: This cross-sectional study randomly selected visitors to the Pakistan Institute of Medical Sciences, Islamabad, Pakistan. Each subject was asked to open his/her mouth as wide as possible while sitting in an upright position, then the distance between the incisal edges of upper and lower right central incisor was measured. Independent t-test and analysis of variance were used, and significant level was set at 5% in all analysis. Results: Of the 497 subjects examined, 52.3% were males and 47.7% were females with age between 15 and 65 years. The mean MMO for all subjects was 58.2mm (standard deviation = 7.92) and ranged between 35 and 71mm. Statistically, the MMO was significantly wider in the males than in females (mean difference = 10.9mm, 95% confidence interval: 9.60, 12.2, P < 0.001). The difference between sexes was also significant in all age groups except in the 56–65 years old. The mean width of MMO declines with increasing age. Conclusion: It is concluded that the mean MMO of Pakistani males is significantly higher than the Pakistani females, and it is influenced by gender and age. The mouth opening reduces with age, and the results of this study are in agreement with the different studies in different countries.